1. Field of the Invention
The invention relates in general to a color correction method and an apparatus of an RGB signal, and more particularly to a color correction method and an apparatus of an RGB signal capable of adjusting the hue (H), saturation (S) and value (V) of the RGB signal respectively, independently and continuously.
2. Description of the Related Art
Color correction such as adjustment of the hue (H), saturation (S) and value (V) of an RGB signal is performed in a liquid crystal display for high quality image. However, the adjustment is often operated in an HSV domain. Consequently, it is required to execute RGB/HSV and HSV/RGB conversions in the process of the adjustment of the hue, saturation and value of the RGB signal. One embodiment of the known RGB/HSV conversions is exemplified below.fmax=max(max(R,G),B);  10fmin=min(min(R,G),B);  20delta=max−fmin;  30RR=(G−B)/delta;  40GG=2+(B−R)/delta;  50BB=4+(R−G)/delta;  60Value=fmax;  70Saturation=(delta/fmax);  80Hue=(fmax==R)×RR+((fmax˜=R)&(fmax==G))×GG+((fmax˜=R)×(fmax˜=G)&(fmax==B))×BB;  90Hue=(H<0)×(H+6×r)+(H>=0)×(H);  100
However, in the process of the RGB/HSV conversion and its inverse conversion, it will result in the problem of discontinuity in the process of color correction of the RGB signal because of the conditional formulae. Hence, the image frame corresponding to the RGB signal is not smooth.